PlayerUnknown's Battlegrounds is on a runaway train of success at the moment. The game recently pushed 5 million copies in sales (which is insane in such a short time), and was recently featured in the Japanese anime Gamers. Take a look:
The game has sold about 1,000,000 copies a month since launch and recently surpassed GTAV in games with the most concurrent users on Steam. At the moment it's not that far away from overtaking Fallout 4 in the 3 spot...which will then only leave CSGO and DOTA 2 left to conquer. I said a couple days ago I didn't think it could do it, but damn this game just keeps getting bigger. Do you have your copy yet?